You can view the most popular tourist destinations in the world on Maps. Here are some tools and sites to find the popular tourist destinations easily.
3D Tourist map
Onion Map introduced a great collection of interactive 3D maps of some of the most world’s popular cities.You can zoom and move around the place just like the Google Maps but this is more clean and interesting. Foreign tourists will also find these maps very useful since all the major city attractions, hotels & restaurants, shopping joints, etc. are very neatly and clearly marked. 
Heatmaps
Ahti Heinla has created an interesting heat map on Google Maps that shows how popular different parts of the world are among tourists. The underlying data for the heat map is sourced entirely from Panoramio. The color yellow on the world map indicates high density of tourists (most of Europe), red indicates medium activity (see Japan) while blue means that destination is less popular with tourists. Places that had no Panoramio photos, and therefore nil tourist activity, are in grey color.
Have you ever heard of the Google service Panoramio. If not, Panoramio is a Google service where anyone can upload photos of places where they visited. It can easily measure the popularity of different regions of the world using the popularity in Panoramio (see the above picture). The idea is simple, the higher the picture count from a region, the more popular that place should be among tourists. Using that simple logic, Ahti Heinla has created a nice heat map on Google Maps, showing popular parts of the world among tourists,and the underlying data for the heat map is sourced entirely from the Panoramio.
